Effect of Preparation on Mercury Levels in Tuna

Effect of Preparation on Mercury Levels in Tuna By Will Plunkett & Chris Winter

Mercury Can Have Harmful Effects On Humans Birth Defects Speech and hearing impairments Decreased Cognitive Functions Tremors (Conniff, 2015) Weakness Loss of coordination (Holistic Dental Institute, 2017)

Mercury Can be Found in Tuna ● Mercury collects in oceans largely because of pollution. ● Bacteria turns mercury into methylmercury through Methylation. ● Mercury bioaccumulates in apex predators such as tuna. ● Humans consume tuna. (Environment and Climate Change Canada, 2017)

The World Eats a Lot of Tuna (Ferdman, 2014)

Research Question Which preparation of tuna has the lowest mercury level and is the safest to eat? Canned Yellowfin, or fresh Yellowfin?

Null Hypothesis There is no statistically significant difference between the mercury levels in different preparations of tuna (canned and fresh Yellowfin)

Alternative Hypotheses 1. Canned tuna will have lower mercury levels because the tuna is caught while younger. 2. Fresh tuna will have lower mercury levels because the canning process may add trace amounts of metals to the fish.

Data measuring (Quantitative) Independent Variable - Preparations of Tuna (Canned or Fresh) Dependent Variable - Mercury Level in Each Preparation of Tuna

Materials Used

Procedure 1. Measure fifteen 2. 5 gram pieces of each preparation of tuna. 2. Measure out 30 cups of distilled water and blend one sample of tuna with 1 cup of distilled water. 3. Test each solution for the amount of mercury using mercury testing strips. Will Blending Tuna

Procedure Continued 4. Record and use the data in a table to calculate descriptive statistics. 5. Using this collected data, make a graph and chart. Blended Tuna

Results-Tables Statistical tests used Mean Median Mode Range Variance Standard Deviation

Results-Graph Mean was used to create a graph of averages

• The null hypothesis was rejected; p (0. 00543) < 0. 05. • Hypothesis 1 is supported. Limited sampling supports that canned tuna is safer to eat: • Canned tuna: average of 0. 0004 ppm mercury. • Fresh tuna: average of 0. 0011 ppm mercury • The data could possibly be incorrect due to errors. Conclusion Canned tuna testing strips after testing Fresh tuna testing strips after testing

Data Discussion The mean calculation of canned tuna was less than that of fresh tuna; SEM of 0. 00013 shows that this data is reflective of the mercury content of all canned tuna. P-Value (0. 00543) indicates that there was a statistically significant difference between each preparation

Possible Errors Amounts of tuna may have been too little to show a notable difference in mercury levels. Tuna could have been contaminated by human touch. Tuna preparations were tested at different times. Blender was not cleaned fully between all trials. Sample size was too small.

Further questions Testing with higher concentration of tuna in mixture. Comparing yellowfin tuna to other types of tuna. Comparing mercury levels in tuna to other apex predatory sea life. Testing for other potentially harmful substances found in tuna.

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